Programa e Resumos - I Congresso Ibérico de Ciência do Solo 2004

I Congresso Ibérico da Ciência do Solo – 15 a 18 de Junho de 2004, Bragança, Portugal
Distribution of Pb added to soils from calcareous parent material.
Isaura Rábago 1 , José Ramón Quintana 2 , Ana María Moreno 2 & Juana González 2
1 CIEMAT, Avda. Complutense 22, 28040 Madrid, Spain – Tel: (34) 91 3466206 – E-mail:
isaura.rabago@ciemat.es
2 Dpto. de Edafología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain –
Tel: (34) 91 3941759 – E-mail: jrquinta@farm.ucm.es
Resumo
Comunicação: Painel
The main objective of this work was to study the Pb distribution, by applying a
sequential extraction procedure, in order to identify the processes that influence metal
mobility and retention in soils developed from calcareous materials.
Two groups of samples were collected, from non-polluted forested areas of Quercus
rotundifolia, according to their carbonate content: soils with no carbonates and soils
with carbonates.
Distribution experiments were carried out adding 200 mg L -1 and 50 mg L -1 of Pb (1:10
soil/ solution) to samples in batch experiments. Retention analyses were carried out
applying the Tessier sequential extraction procedure.
All the soil samples had a pH above the neutrality. There were a group of soils with no
carbonates and samples with a content in carbonates between 22 and 63%. The organic
matter contents were similar for both groups of soils. The CEC and the percentages of
clay were higher for the non- carbonated soils.
In both treatments of contamination, the carbonates and the iron and manganese oxides
are the main fractions involved in the retention of Pb, independently of the added
concentration. The soluble fraction was very low (